A non-coated porcelain surface becomes wet, allowing conductive solutions to form and leading to leakage currents that can eventually cause a flashover. Dow Corning silicone compounds provide hydrophobic coatings that prevent flashovers even after long periods of time in contaminated conditions. The coatings maintain their hydrophobicity and original color over many years when used on voltages from 11kv to 500kv, making them suitable for coastal environments.